Since appropriate antibiotic therapy is the most crucial factor in the treatment of patients with bacterial meningitis, rapid accurate identification of the infecting agent is critical in the initial evaluation and management of these patients. Traditional staining techniques provide accurate bacteriologic data in only 60 to 70 percent of cases of bacterial meningitis. Thus, there is still a need for a rapid, sensitive test which is broad enough to recognize meningeal infection caused by common pathogens and to identify other bacterial pathogens as well. The use of gas chromatography (GLC), in combination with computer techniques and with mass spectrometry (MS), permits the separation, quantitation, and identification of a wide variety of trace constituents of physiological fluids. Gas chromatography has already proven to be of value in the identification of bacteria and the diagnosis of systematic bacterial and viral infection in experimental animals. Its potential as a clinical diagnostic tool has not yet been fully realized. The basic goal of the proposed protocol is to utilize GLC profile analysis for the rapid diagnosis of bacterial meningitis. Initial studies include the development of rapid extraction techniques and GLC column conditions appropriate for spinal fluid profile analysis. These techniques will be used to quantitatively determine chromatographic patterns of spinal fluid from normal rabbits and animals infected with N. meningitides, S. aureus, E. coli, and P. aeruginosa. Peaks that appear to be specific for each of the infection models will be identified by GLC-MS. These methods will then be applied to spinal fluid obtained from humans with no neurological disease as well as with aseptic and bacterial meningitis. These techniques will then be adapted to routine clinical laboratory use using only simplified GLC methodology and equipment without MS or computer systems.